1. Field of the Invention
The invention relates to a vehicle component and an engine component for supplying secondary air. More particularly, the invention relates to a vehicle component and an engine component for supplying secondary air having a clamping portion which is necessary during manufacture of the parts that has been left remaining.
2. Description of the Related Art
When performing processes such as forming, assembling, and welding a part (hereinafter also referred to as “work”) using production equipment during manufacture of the part, typically the work is first positioned on the production equipment and then clamped down at an appropriate portion by a suitable method according to the degree necessary to ensure manufacturing quality of the work, for example. If the work is not able to be held sufficiently by the production equipment due to, for example, the shape or strength of the work, the work may be provided with a special clamping portion so that it can be easily held. With parts such as those formed by press working which use a thin metal sheet as the raw material, for example, the work may not be able to be held sufficiently during press forming using only the portion necessary for the work to function. Also, if a portion necessary for the work to function is carelessly or improperly held, that portion may be damaged. Therefore, such parts may be provided with a clamping portion that is separate from portion necessary for the work to function. Japanese Patent Application Publication No. JP-A-2004-162682, for example, describes technology using a press-formed part.
More specifically, Japanese Patent Application Publication No. JP-A-2004-162682 describes a secondary air supply structure to supply secondary air to an exhaust port of an internal combustion engine. Japanese Patent Application Publication No. JP-A-2004-162682 also describes a heat insulator for covering an exhaust manifold as a constituent element of this secondary air supply structure. The heat insulator includes a heat insulator cover portion and a heat insulator flange portion. A groove having an open portion with a concave cross section that extends in the direction in which the cylinders are aligned is formed in the heat insulator flange portion. Japanese Patent Application Publication No. JP-A-2004-162682 describes press forming the groove into a flat heat insulator flange portion in order to form the groove by a simpler manufacturing process.
Meanwhile, Japanese Patent Application Publication No. JP-A-2004-211659 describes a heat insulator having a structure in which front heat insulator and a back heat insulator are laminated together. Japanese Patent Application Publication No. JP-A-2004-211659 describes manufacturing the heat insulator by press forming the front and back heat insulators with two thin metal sheets stacked on top of one another so that the front and back heat insulators will be generally the same shape.
The clamping portion described above may be left on the part even after the part is finished, even though it is no longer necessary and increases the weight of the part. The reason for this is that removing the clamping portion after the part is finished would require a change in a pre-existing manufacturing process due to the addition of special processing equipment necessary for the removing the clamping portion, for example, and such an investment in new equipment and the like would greatly increase costs. Therefore, the clamping portion, although unnecessary for the part to function, is often left on to avoid this. Also, although there is no specific mention of this clamping portion in Japanese Patent Application Publication No. JP-A-2004-162682 and Japanese Patent Application Publication No. JP-A-2004-211659, when a clamping portion is left on a part such as the insulator described above which is made of thin metal sheets, not only does it increase the weight, but it may also produce vibration noise in the vehicle.